Barrel valve

ABSTRACT

A barrel valve assembly for a fluid distribution manifold. A barrel valve body has an off-axis passage with substantially linear walls therethrough, allowing for a substantially linear relationship between fluid flow through the body and angular rotation of the barrel valve within the manifold. The barrel valve thus requires a smaller working environment for the valve assembly, providing benefits in terms of assembly size and weight.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the benefit of priority U.S. ProvisionalApplication No. 62/983,260, filed on Feb. 28, 2020, the entirety ofwhich is incorporated herein by reference.

BACKGROUND

Current air distribution manifolds can be large, heavy, and bulky.Typically, commercially available valves are associated with fluid flowchannels through modules external to a manifold or housing containingthe flow channels, thus increasing the volume required to accommodatesuch a valved manifold.

Further, precise metering of flow volumes using currently availablevalves, such as ball valves, is challenging. This is attributable to thefact that a given angular rotation of a common valve results indiffering changes in flow volumes, depending upon how far the valve isalready open or closed. For example, a typical ball valve utilizes around port. If the valve is closed, a given angular rotation of thevalve in the open direction will reveal a relatively small portion ofthe round port. However, if the valve is already partly open, the samedegree of angular rotation will increase the flow volume exponentially,given the round profile of the port. Predictable flow volume control isthus a challenge.

While some available valves can provide more precise control over flowvolumes, they have their own associated drawbacks. For example, atypical gate valve can provide accurate and precise control over fluidflows, but require multiple revolutions to vary from closed to fullyopen.

Thus, there exists a need for a smaller, lighter and more ergonomicvalve that can be implemented directly into a flow channel distributionmanifold without the requirement for a bulky external housing, thatprovides a linear relationship between actuation and flow control, andthat requires a minimal amount of actuation for a full range of flowcontrol. Such a device, if provided, would enable unique and beneficialfunctional control over fluid flows in a compact space.

BRIEF SUMMARY

The present application is directed to a fluid metering valve that maybe integrated directly into a flow channel manifold intermediate twoflow channels. The fluid metering valve is provided with a barrel valvehaving a passage that extends off-axis along a length of and through thebarrel valve. When in a closed orientation, a solid portion of thebarrel valve blocks the passage intermediate the two flow channels.Rotation of the barrel valve exposes a portion of the passageintermediate the two flow channels, allowing a metered amount of fluidflow therebetween. The off-axis passage and associated solid portion ofthe barrel valve enable the thickness of the distribution manifoldreceiving the valve to be minimized, thereby reducing the overallfootprint and weight of the manifold.

Beneficially, the passage is formed with a square, rectangular orrounded rectangular cross-section. Such a configuration enables a linearor near linear relationship between change in fluid flow volume throughthe passage and change in angular position of the barrel valve relativeto the distribution manifold. This linearity provides a more predictableresponse to valve manipulation. In addition, such a configurationenables the valve to change from fully closed to fully open in less thanone-hundred twenty degrees of barrel valve rotation and preferablyninety degrees or less, allowing for a faster rate of fluid flowincrease or decrease.

A further advantage enabled by the presently disclosed fluid meteringvalve is that the volume of material in the barrel valve may beminimized, thereby contributing to weight and size reduction.

In an aspect of the present embodiments, a fluid metering valve assemblyincludes a barrel valve having a valve body, the body beingsubstantially symmetrical about an axis of symmetry. The valve body hasfirst and opposite second ends along the body axis of symmetry and apassage formed laterally through the body.

The passage comprises mutually parallel, planar first and second sidewalls, each lying in respective plane that is parallel to the body axisof symmetry. The passage also comprises a first planar end wall,intermediate ends of the first and second side walls most proximate thebody first end, and a second planar end wall, intermediate ends of thefirst and second side walls most proximate the body second end. Thefirst end wall is parallel to the second end wall and both the first andsecond end walls lie in a respective plane that is orthogonal to thebody axis of symmetry.

The passage also comprises transition regions between the first planarend wall and the ends of each of the first and second side walls mostproximate the body first end and between the second planar end wall andthe ends of each of the first and second side walls most proximate thebody second end. In an embodiment, the transition regions are each aright angle, whereby a cross-section of the passage coincident with thevalve body axis of symmetry is a rectangle or square. In anotherembodiment, the transition regions are each a circular arc having acentral angle of ninety degrees, whereby a cross-section of the passagecoincident with the valve body axis of symmetry is a rounded rectangleor rounded square.

In another aspect of the present embodiments, a method of selectivelyinterconnecting mutually adjacent first and second flow channels in adistribution manifold using a fluid metering valve is disclosed. Themethod includes providing a barrier wall intermediate and separating thefirst and second flow channels, providing a semi-cylindrical borethrough the barrier wall, the bore forming an aperture in the barrierwall between the first and second flow channels, and disposing a barrelvalve having a valve body within the barrier wall bore. The valve bodyis substantially symmetrical about a respective axis of symmetry andcomprises first and opposite second ends along the body axis of symmetryand a passage formed laterally through the body.

The passage comprises mutually parallel, planar first and second sidewalls, each lying in respective plane that is parallel to the body axisof symmetry, a first planar end wall, intermediate ends of the first andsecond side walls most proximate the body first end, and a second planarend wall, intermediate ends of the first and second side walls mostproximate the body second end. The first end wall is parallel to thesecond end wall and both the first and second end walls lie in arespective plane that is orthogonal to the body axis of symmetry.

The passage further comprises transition regions between the firstplanar end wall and the ends of each of the first and second side wallsmost proximate the body first end and between the second planar end walland the ends of each of the first and second side walls most proximatethe body second end. In an embodiment, the transition regions are each aright angle, whereby a cross-section of the passage coincident with thevalve body axis of symmetry is a rectangle or square. In anotherembodiment, the transition regions are each a circular arc having acentral angle of ninety degrees, whereby a cross-section of the passagecoincident with the valve body axis of symmetry is a rounded rectangleor rounded square.

The method further comprises selectively rotating the barrel valvewithin the bore to selectively align the passage relative to the firstand second flow channels, whereby at least a portion of the passage isexposed to both the first and second flow channels, the first and secondflow channels being in mutual fluid communication therethrough, orwhereby the valve body is intermediate the first and second flowchannels within the bore, the first and second flow channels beingmutually isolated thereby.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a perspective view of a distribution manifold having a valveassembly according to the present disclosure;

FIG. 1B is an elevation view of the distribution manifold of FIG. 1A;

FIG. 2A is a perspective view of a barrel valve for use in the valveassembly of FIGS. 1A and 1B;

FIG. 2B is a side elevation view of the barrel valve of FIG. 2A;

FIG. 2C is an end elevation view of the barrel valve of FIGS. 2A and 2B;

FIG. 2D is a side elevation view of the barrel valve of FIG. 2A.

FIG. 2E is a side elevation view of the barrel valve of FIG. 2A.

FIG. 3A is a top section view of the manifold of FIG. 1B taken alongsection lines 3-3 illustrating the barrel valve of FIGS. 2A, 2B and 2Cin a closed orientation relative to the distribution manifold;

FIG. 3B is a top section view of the manifold of FIG. 1B taken alongsection lines 3-3 illustrating the barrel valve of FIGS. 2A, 2B and 2Cin an open orientation relative to the distribution manifold; and

FIG. 4 is an exploded, perspective view of the distribution manifold ofFIGS. 1A and 1B having a valve assembly, including the barrel valve ofFIGS. 2A, 2B and 2C.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

FIGS. 1A and 1B show a particular embodiment of a distribution manifold100 having a valve assembly 120 disposed therein according to thepresent disclosure. The illustrated manifold includes first and secondmutually parallel flow channels 102, 104, the flow channels being inselective mutual communication via the valve assembly. The manifold isalso visible in a horizontal section views in FIGS. 3A and 3B.

In the illustrated embodiment, the first flow channel 102 terminateswithin the manifold, opposite an open end 106, while the second flowchannel 104 has dual open ends 108, 110, though the presently disclosedvalve assembly 120 is operable in association with other manifoldembodiments as well. Each flow channel open end may be provided withsuitable features to facilitate the selective coupling offluid-conveying members such as hoses, tubes or pipes. These featuresmay be, for example, mutually cooperating threads disposed on or in amanifold open end and on or in an end of the cooperating fluid-conveyingmember. Alternatively, mutually cooperating male and female quickconnect fittings may be employed for purposes of selective coupling.

As shown in FIGS. 3A and 3B, the substantially cylindrical valveassembly 120 is disposable in a semi-cylindrical bore 162 formed withina barrier wall 112 intermediate the first and second mutually parallelflow channels 102, 104. As illustrated in the exploded view of FIG. 4 ,the valve assembly includes a barrel valve 122. In certain embodimentsof the valve assembly, additional elements are included, such as one ormore O-rings 124, also referred to as circular seals, and a liner 126,as discussed below.

The barrel valve 122 is depicted in detail in FIGS. 2A, 2B, 2C, 2D, and2E. The barrel valve has a substantially cylindrical body 130 having anaxis of symmetry 138 and first and second opposite ends 132, 134.Intermediate the two ends, a passage 140 extends laterally across andthrough the body. The passage is comprised of two mutually parallel,planar side walls 142 and two mutually parallel, planar end walls 146.The side walls each lie in a plane that is parallel to the axis ofsymmetry. A first end wall is intermediate the ends of a first side walland a second side wall that are most proximate the body first end, whilea second end wall is intermediate the ends of the first side wall andthe second side wall that are most proximate the body second end. Theend walls each lie within a respective plane that is orthogonal to thebody axis of symmetry. A plane 136 intermediate or halfway between thefirst and second side walls is parallel to but offset or spaced from thebody axis of symmetry by a non-zero distance “d”.

Transitions 148 extend between the first planar end wall 146 and theends of the first and second side walls 142 most proximate the bodyfirst end 132 and between the second planar end wall and the ends of thefirst and second side walls most proximate the body second end 134. Thebody axis 138 of symmetry orthogonally intersects either both first andopposite second end walls of the passage or two opposing transitions.

As depicted, the passage 140 is a rounded rectangle in cross-sectionalshape as a result of each transition 148 being a circular arc having acentral angle of ninety degrees. In alternative embodiments, the passagemay present a rounded square. In yet further embodiments, eachtransition 148 is a right angle, whereby the passage is a rectangle orsquare. In all embodiments, however, it is preferable to havesubstantially linear side walls 142 and end walls 146 therebetween.These characteristics provide for a substantially linear response inadjustment of flow rate with respect to degree of barrel valve 122rotation, a significant improvement with respect to prior art valvesused for similar purposes. A full range of flow control is thus enabledwithin 120 degrees of barrel valve 122 rotation, or more preferably,within 90 degrees of barrel valve rotation.

The plane 136 intermediate the first and second side walls 142 beingoffset or spaced from the body axis of symmetry 138 places the passage140 off axis relative to the axis of the valve body 130. Thischaracteristic is useful in that a portion of the body may extend intoone of the flow channels 102, 104, beyond its seal, while an oppositeportion of the valve body extends across a semi-cylindrical bore 162 inthe manifold barrier wall 112 (discussed subsequently), therebypreventing fluid flow therethrough. This orientation is depicted in FIG.3A and results in an ability to utilize a thinner barrier wall betweenflow channels, thus reducing the overall footprint and weight of thedistribution manifold.

In an embodiment, the barrel valve 122 has at least one rotationlimiting channel 150 formed on the body 130. In FIGS. 2A and 4 , twosuch channels are provided, one proximate the body first end 132 and oneproximate the body second end 134. These channels are each intended toreceive and cooperate with a respective fixed projection (not shown)extending radially inward from a portion of the distribution manifold100 barrier wall 112. Rotation of the barrel valve is thus limited bythe radial distance that the rotation limiting channel or channelsextend about the body. In one embodiment, the channel or channels extendin an arc of 120 degrees or less about the body axis of symmetry 138 onthe outer surface of the body. In a further embodiment, the channel orchannels extend in an arc of roughly ninety degrees or less.

In order to minimize weight and the quantity of material required tofabricate the valve assembly 120, the valve body 130 may be providedwith a cutout 144 formed on an outer surface of the body. In theillustrated embodiment of FIGS. 2A and 2B, the cutout is formed as asemi-cylindrical depression opposite one of the side walls 142. Thecutout, if provided in other embodiments, may be provided with a varietyof shapes as long as the structural integrity of the valve body formingthe passage is not sacrificed.

The barrel valve 122 as described in the foregoing may be disposedwithin a semi-cylindrical bore 162 extending into the barrier wall 112intermediate the first and second flow channels 102, 104. A sealingeffect between the barrel valve and the bore may be achieved fromappropriate lapping, grinding, burnishing or other surface treatment ofthe respective parts. Such treatment may vary, depending upon thematerials chosen, which itself may be influenced by the specific fluidflow application involved. Suitable materials may include stainlesssteel for the barrel valve, which may be burnished for a closertolerance fit with respect to the bore. However, other materials mayalso be selected, including thermoplastics or composites, with orwithout coatings or platings as desired or required. Factors varyingwith the application may include sealing pressures, cost of manufacture,fluid compatibility and reactivity, and rotational force required tomanipulate the barrel valve.

However, in other embodiments, the valve assembly 120 is provided withadditional elements, as follows. In such a further embodiment of thevalve assembly 120, the valve body 130 is also provided with at leastone seal-receiving circular groove 152. As shown in the embodimentillustrated in FIGS. 2A, 2B, and 4 , two such grooves are provided, oneon either side of the passage 140. The grooves are mutually parallel andare configured to receive O-rings or circular seals 124 therein. Thisembodiment of the valve assembly, comprising a barrel valve 122 andO-rings, may be installed directly into the semi-cylindrical bore 162 inthe barrier wall 112, the O-rings bearing against the bore walls as thevalve assembly is selectively rotated about its axis of symmetry 138.

In yet a further embodiment, the valve assembly 120 further comprises,in addition to a barrel valve 122 and O-rings 124, a liner 126 comprisedof a substantially cylindrical shell with a respective axis of symmetry128. The liner is intended for stationary installation into the bore 162in the barrier wall 112. An inner diameter of the liner is selected toreceive the barrel valve therein with an outer peripheral extent of theO-rings 124 configured for physical engagement with the inner surface ofthe liner, the O-rings sliding against the inner surface of the linerwhen the barrel valve 122 is rotated. A pair of mutually oppositeapertures 164 are provided through the liner. When the barrel valve isdisposed within the liner, the body may be rotated about its axis ofsymmetry 138, coincident with the axis of symmetry of the liner, suchthat the valve body passage 140 may be aligned with the mutuallyopposite liner apertures, when the valve assembly is in an openorientation, out of alignment with the mutually opposite linerapertures, when the valve assembly is in a closed orientation, or atsome rotational orientation such that a portion of the valve bodypassage is exposed within the mutually opposite liner apertures.

The liner 126 may be provided with one or more orifices 160. When thebarrel valve 122 is installed within the liner, each of the at least onerotation limiting channels 150 formed on the body 130 is beneath acorresponding liner orifice. In this manner, a fixed projection (notshown) extending radially inward from a portion of the distributionmanifold 100 barrier wall 112 may extend through each liner orifice andinto the corresponding and underlying rotation limiting channel.

The liner 126 may be provided of a variety of materials, including glassreinforced PTFE, brass, bronze, nylon, and acetal variants, with orwithout O-rings which, if used, may be made of Buna N. The sealing linermay also be provided of stainless steel, which may be burnished, for usewith or without O-rings intermediate the liner and barrel valve 122.

Further still, an embodiment of the valve assembly 120 comprises thebarrel valve 122 and liner 126, without O-rings 124.

As best seen in FIGS. 2A and 2C, the barrel valve 122 second end 134 isprovided with a bore 166 formed therein. The bore may be provided withphysical features for selectively engaging a separate member (not shown)that may be manually or automatically rotated about the valve body 130axis of symmetry 138, thereby rotating the barrel valve relative to thedistribution manifold 100. For example, the bore may be provided withinternal spiral threads. The rotation member is then provided with acylindrical projection having complimentary spiral threads forengagement within the bore. Either or both barrel valve ends may havesuch physical features for selective engagement with a rotation member.

Also disclosed is a method of selectively interconnecting mutuallyadjacent flow channels 102, 104 in a distribution manifold 100 using afluid metering valve assembly 120 including the barrel valve 122described above, with or without the O-rings 124 and/or liner 126. Themethod includes providing a barrier wall 112 intermediate and separatingfirst and second flow channels, forming a semi-cylindrical bore 162within the barrier wall thereby forming an aperture intermediate the twoflow channels, and disposing a barrel valve such as described in theforegoing into the bore. The barrel valve may then be selectivelyrotated within the bore to align the passage 140 relative to the firstand second flow channels. The two flow channels may thus be in varyingdegrees of fluid communication via the valve body 130 passage or may bemutually isolated by the valve body, depending upon the rotationalorientation of the barrel valve within the bore.

The method may be practiced utilizing the barrel valve 122 alone withinthe barrier wall 112 bore 162, or may be practiced with a valve assembly120 including the barrel valve and at least one O-ring 124 disposedwithin a respective circular groove 152. Further, the method may furtherbe practiced with a valve assembly including the foregoing elements,along with the substantially cylindrical liner 126 as described above.In all embodiments, rotation of the barrel valve relative to the barrierwall bore results in a selective amount of fluid communication betweenthe first and second flow channels 102, 104 via the passage 140, or nofluid communication at all.

Alternative embodiments of the subject matter of this application willbecome apparent to one of ordinary skill in the art to which the presentinvention pertains, without departing from its spirit and scope. It isto be understood that no limitation with respect to specific embodimentsshown here is intended or inferred.

What is claimed is:
 1. A fluid metering valve assembly, comprising: abarrel valve comprising: a valve body being substantially symmetricalabout an axis of symmetry, first and opposite second ends along the bodyaxis of symmetry, and a passage formed laterally through the body, thepassage comprising: mutually parallel, planar first and second sidewalls, each lying in a respective plane that is parallel to the bodyaxis of symmetry; a first planar end wall, intermediate ends of thefirst and second side walls most proximate the first end of the body; asecond planar end wall, intermediate ends of the first and second sidewalls most proximate the second end of the body, the first planar endwall being parallel to the second planar end wall and both the first andsecond planar end walls lying in a respective plane that is orthogonalto the body axis of symmetry; and transition regions between the firstplanar end wall and the ends of each of the first and second side wallsmost proximate the body first end and between the second planar end walland the ends of each of the first and second side walls most proximatethe body second end; a substantially cylindrical liner having an axis ofsymmetry and an inner diameter selected to slidably receive the bodytherein and having a pair of mutually opposite apertures that may befully, partially, or not aligned with the body passage when the body isreceived within the substantially cylindrical liner and the body isrotated about the body axis of symmetry, wherein the body axis ofsymmetry and the substantially cylindrical liner axis of symmetry arecoaxial when the body is received within the substantially cylindricalliner; wherein the body has at least one rotation limiting channelformed on an outer surface thereof, the at least one rotation limitingchannel extending in a plane orthogonal to the body axis of symmetry andin an arc of one-hundred twenty degrees or less about the body axis ofsymmetry on the outer surface of the body, and wherein the substantiallycylindrical liner comprises at least one orifice formed through thesubstantially cylindrical liner, each of the at least one orifice beingaligned with a respective one of the at least one rotation limitingchannel formed on the body outer surface when the body is disposedwithin the substantially cylindrical liner.
 2. The fluid metering valveassembly of claim 1, wherein the transition regions are each a rightangle, and whereby a cross-section of the passage coincident with thevalve body axis of symmetry is a rectangle.
 3. The fluid metering valveassembly of claim 1, wherein the transition regions are each a rightangle, and whereby a cross-section of the passage coincident with thevalve body axis of symmetry is a square.
 4. The fluid metering valveassembly of claim 1, wherein the transition regions are each a circulararc having a central angle of ninety degrees, whereby a cross-section ofthe passage coincident with the valve body axis of symmetry is a roundedrectangle.
 5. The fluid metering valve assembly of claim 1, wherein thetransition regions are each a circular arc having a central angle ofninety degrees, whereby a cross-section of the passage coincident withthe valve body axis of symmetry is a rounded square.
 6. The fluidmetering valve assembly of claim 1, wherein the body axis of symmetryintersects each of the first and opposite second end walls of thepassage.
 7. The fluid metering valve assembly of claim 1, wherein aplane equidistant to each of the first and second side walls is parallelto but offset from the body axis of symmetry.
 8. The fluid meteringvalve assembly of claim 1, wherein the body further comprises a cutoutformed on an outer surface thereof opposite one of the first and secondside walls.
 9. The fluid metering valve assembly of claim 1, wherein thebody has at least one seal-receiving circular groove formed on an outersurface thereof and in a plane orthogonal to the body axis of symmetry.10. The fluid metering valve assembly of claim 9, further comprising asubstantially circular seal disposed within each of the at least oneseal-receiving circular grooves.
 11. The fluid metering valve assemblyof claim 10, wherein an outer peripheral extent of the at least onecircular seal is configured for physical engagement with an innersurface of the substantially cylindrical liner.
 12. The fluid meteringvalve assembly of claim 1, wherein at least one of the first andopposite second ends of the body have a bore formed therein.
 13. Thefluid metering valve assembly of claim 12, wherein the at least one borehas an internal, spiral thread for selectively receiving a cylindricalprojection of a member therein, the cylindrical projection having anexternal spiral thread formed thereon.
 14. The fluid metering valveassembly of claim 13, wherein the member is for adjusting a rotationalposition of the body about the body axis of symmetry.
 15. An airdistribution manifold, comprising: a first flow channel; a second flowchannel adjacent to the first flow channel; a barrier wall intermediatethe first and second flow channels; and a barrel valve according toclaim 1 intermediate the first and second flow channels in the barrierwall for enabling selective fluid communication between the first andsecond flow channels.
 16. A method of selectively interconnectingmutually adjacent first and second flow channels in a distributionmanifold using a fluid metering valve, comprising: providing a barrierwall intermediate and separating the first and second flow channels;providing a semi-cylindrical bore through the barrier wall, the boreforming an aperture in the barrier wall between the first and secondflow channels; disposing a barrel valve having a valve body within thebarrier wall bore, the body being substantially symmetrical about anaxis of symmetry, the body comprising: first and opposite second endsalong the body axis of symmetry, and a passage formed laterally throughthe body, the passage comprising: mutually parallel, planar first andsecond side walls, each lying in a respective plane that is parallel tothe body axis of symmetry; a first planar end wall, intermediate ends ofthe first and second side walls most proximate the first end of thebody; a second planar end wall, intermediate ends of the first andsecond side walls most proximate the second end of the body, the firstplanar end wall being parallel to the second planar end wall and boththe first and second planar end walls lying in a respective plane thatis orthogonal to the body axis of symmetry; and transition regionsbetween the first planar end wall and the ends of each of the first andsecond side walls most proximate the body first end and between thesecond planar end wall and the ends of each of the first and second sidewalls most proximate the body second end; and selectively rotating thebarrel valve within the bore to selectively align the passage relativeto the first and second flow channels, whereby at least a portion of thepassage is exposed to both the first and second flow channels, the firstand second flow channels being in mutual fluid communicationtherethrough, or whereby the valve body is intermediate the first andsecond flow channels within the bore, the first and second flow channelsbeing mutually isolated thereby, wherein the body has at least oneseal-receiving circular groove formed on an outer surface thereof and ina plane orthogonal to the body axis of symmetry; disposing asubstantially circular seal within each of the at least oneseal-receiving circular grooves; and disposing a substantiallycylindrical liner within the barrier wall bore intermediate the barrierwall and the valve body, the liner having an axis of symmetry and aninner diameter selected to receive the body therein with an outerperipheral extent of the at least one circular seal configured forphysical engagement with an inner surface of the liner, wherein the bodyaxis of symmetry and the liner axis of symmetry are coaxial when thebody is received within the liner, and wherein the liner further havinga pair of mutually opposite apertures that may align with the bodypassage when the body is received within the liner and the body isrotated about the body axis of symmetry, wherein the liner comprises atleast one aperture formed through the liner, each of an at least oneaperture being aligned with a respective one of the at least onerotation limiting channel formed on a body outer surface when the bodyis disposed within the liner.
 17. The method of claim 16, wherein thetransition regions are each a right angle, and whereby a cross-sectionof the passage coincident with the valve body axis of symmetry is arectangle.
 18. The method of claim 16, wherein the transition regionsare each a right angle, and whereby a cross-section of the passagecoincident with the valve body axis of symmetry is a square.
 19. Themethod of claim 16, wherein the transition regions are each a circulararc having a central angle of ninety degrees, whereby a cross-section ofthe passage coincident with the valve body axis of symmetry is a roundedrectangle.
 20. The method of claim 16, wherein the transition regionsare each a circular arc having a central angle of ninety degrees,whereby a cross-section of the passage coincident with the valve bodyaxis of symmetry is a rounded square.
 21. The method of claim 16,wherein the body axis of symmetry intersects each of the first andopposite second end walls of the passage.
 22. The method of claim 16,wherein a plane equidistant to each of the first and second side wallsis parallel to but offset from the body axis of symmetry.
 23. The methodof claim 16, wherein the body further comprises a cutout formed on anouter surface thereof opposite one of the first and second side walls.24. The method of claim 16, wherein at least one of the first andopposite second ends of the body have an end bore formed therein. 25.The method of claim 24, further comprising disposing an actuation memberhaving a cylindrical projection within the at least one end bore, theactuation member having an external spiral thread formed thereon, andwherein the at least one end bore has an internal, spiral thread forselectively receiving the actuation member therein.
 26. The method ofclaim 25, wherein the actuation member is selectively rotated, therebyselectively rotating the valve body within the barrier wall bore aboutthe body axis of symmetry.
 27. A method of selectively interconnectingmutually adjacent first and second flow channels in a distributionmanifold using a fluid metering valve, comprising: providing a barrierwall intermediate and separating the first and second flow channels;providing a semi-cylindrical bore through the barrier wall, the boreforming an aperture in the barrier wall between the first and secondflow channels; disposing a barrel valve having a valve body within thebarrier wall bore, the body being substantially symmetrical about anaxis of symmetry, the body comprising: first and opposite second endsalong the body axis of symmetry, and a passage formed laterally throughthe body, the passage comprising: mutually parallel, planar first andsecond side walls, each lying in a respective plane that is parallel tothe body axis of symmetry; a first planar end wall, intermediate ends ofthe first and second side walls most proximate the first end of thebody; a second planar end wall, intermediate ends of the first andsecond side walls most proximate the second end of the body, the firstplanar end wall being parallel to the second planar end wall and boththe first and second planar end walls lying in a respective plane thatis orthogonal to the body axis of symmetry; and transition regionsbetween the first planar end wall and the ends of each of the first andsecond side walls most proximate the body first end and between thesecond planar end wall and the ends of each of the first and second sidewalls most proximate the body second end; selectively rotating thebarrel valve within the bore to selectively align the passage relativeto the first and second flow channels, whereby at least a portion of thepassage is exposed to both the first and second flow channels, the firstand second flow channels being in mutual fluid communicationtherethrough, or whereby the valve body is intermediate the first andsecond flow channels within the bore, the first and second flow channelsbeing mutually isolated thereby; and disposing a substantiallycylindrical liner within the barrier wall intermediate the barrier walland the valve body, the liner having an axis of symmetry and an innerdiameter selected to slidably receive the body therein and having a pairof mutually opposite apertures that may be fully, partially, or notaligned with the body passage when the body is received within the linerand the body is rotated about the body axis of symmetry, wherein thebody axis of symmetry and the liner axis of symmetry are coaxial whenthe body is received within the liner, wherein the body has at least onerotation limiting channel formed on an outer surface thereof, the atleast one rotation limiting channel extending in a plane orthogonal tothe body axis of symmetry and in an arc of one-hundred twenty degrees orless about the body axis of symmetry on the outer surface of the body,and wherein the liner comprises at least one orifice formed through theliner, each of the at least one orifice being aligned with a respectiveone of the at least one rotation limiting channel formed on the bodyouter surface when the body is disposed within the liner.